Websites claiming to help people win back bank charges are still encouraging consumers to sign up for their services, as consumer groups warn that their claims are unlikely to be succcessful.

Yesterday, the supreme court delivered a shock decision when it ruled that the Office of Fair Trading (OFT) could not challenge overdraft charges because it does not have the power to decide whether they are unfair.

The case was brought between the OFT and seven banks and one building society in reaction to the increasing number of current account customers trying to reclaim overdraft fees paid since 2001.

During that time dozens of websites appeared claiming to help people win back their charges. These are run by claims management companies on a no-win no-fee basis. The websites do not charge an up front fee for handling the cases, but instead take a typical 25% of any money a customer wins back.

They also levy cancellation charges if people begin a claim but change their mind.

Yesterday the websites were in disarray, with many posting holding messages on their front pages saying they were considering the supreme court verdict before advising consumers.

Today, a number of them have been updated to say that consumers should continue to approach them. ReclaimUK.com had a notice up today that said: "We are deeply disappointed with the Supreme Court ruling, but will continue to fight on behalf of our clients.

"We are confident that these Charges can still be deemed unfair, and therefore refunded to you under different consumer regulations which the Test Case did not address."

Meanwhile, Phoenix Claims Ltd stated: "Phoenix Claims will now be amending all claims which were previously on hold to include Regulations 5 & 8 instead of Regulation 6. We are submitting new claims straightaway citing Regulations 5 & 8. Be one of the first to get your claim for refund submitted with the new regulations."

Yesterday, the supreme court ruled that bank charges could not be judged to be priced unfairly, which falls under clause 6 in the Unfair Terms for Consumer Credit Regulations.

Some legal experts have suggested they could be tested under clause 5 on the basis that peoples' contracts with the banks weren't negotiated individually, so they must have been made in good faith and should not cause a significant imbalance to the detriment of the consumer. Clause 8 says that an unfair term in a contract concluded with a consumer by a seller or supplier shall not be binding on the consumer.

However, the judges gave no indication that cases brought under these clauses would be any more successful.

Martin Lewis, founder of website MoneySavingExpert.com, who was at the forefront of the campaign to win back bank charges, said he was "looking to hire a top banking QC to see if it's possible to redraft our legal templates to amend the claim for the new rules."

But he remained pessimistic. "My view is there is a 10-20% chance only of most people now getting past charges back," he wrote on his website today.

The consumer group Which? warned people to avoid claims management company websites. "The outlook is bleak for anyone with an outstanding claim and we are concerned that yesterday's ruling could drive people into the arms of unscrupulous claims handlers," chief executive, Peter Vicary-Smith, said.

"Beware of companies who contact you promising to get your bank charges back and never pay an upfront fee."